U.S. patent number 5,492,532 [Application Number 08/290,139] was granted by the patent office on 1996-02-20 for balloon catheter.
This patent grant is currently assigned to B. Braun Medical, Inc.. Invention is credited to Edward A. Barlow, William P. Ryan.
United States Patent |
5,492,532 |
Ryan , et al. |
February 20, 1996 |
Balloon catheter
Abstract
A balloon consisting of braided fibers encapsulated between two
plastic elastomeric materials affixes to a distal end of a
catheter. The braided fibers provide reinforcement to contain
pressure and determine the maximum diameter of the balloon on
expansion. The elastomeric material provides for fluid containment
and collapsing of the balloon after pressurization. An embedded
spring in an elastomeric material internal to the catheter provides
memory to assist in collapsing the balloon after pressurization.
The embedded spring extends from the distal end of the catheter
towards the proximal end of the catheter along a substantial length
of the catheter. The catheter with the balloon are in a multilumen
configuration or in a coaxial configuration. A guidewire passage
extends through the elastomeric material with the embedded spring.
An alternative embodiment illustrates a hub with a movable internal
seal and inner tube connected to a balloon catheter tip with a free
space collapsement spring. The movable inner seal also assists in
spring collapsement and in shortening of the balloon structure for
maximum allowable radial inflation. A distal portion of a balloon
catheter includes a compressible spring which is free floating
within a tubular interior area and having no embedding material
about it. A hub is also included for use with a catheter having an
extended length balloon. A telescoping tube assembly contains a
flared member for front loading of a guide wire.
Inventors: |
Ryan; William P. (Minnetonka,
MN), Barlow; Edward A. (Bloomington, MN) |
Assignee: |
B. Braun Medical, Inc.
(Plymouth, MN)
|
Family
ID: |
27406367 |
Appl.
No.: |
08/290,139 |
Filed: |
August 15, 1994 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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953481 |
Sep 29, 1992 |
5338299 |
|
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871722 |
Apr 21, 1992 |
5171297 |
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324913 |
Mar 17, 1989 |
5112304 |
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Current U.S.
Class: |
604/103.09;
604/523; 606/191; 606/194 |
Current CPC
Class: |
A61M
25/104 (20130101); A61M 2025/1075 (20130101) |
Current International
Class: |
A61M
29/02 (20060101); A61M 029/00 () |
Field of
Search: |
;128/657
;604/96,97,98,99,100,101,102,103,280,283 ;606/191,192,194,195 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Maglione; Corrine M.
Assistant Examiner: Gring; N. Kent
Attorney, Agent or Firm: Skinner, Jr.; Joel D. Jaeger; Hugh
D.
Parent Case Text
CROSS REFERENCES TO CO-PENDING APPLICATIONS
This patent application is a continuation-in-part of U.S. Ser No.
07/953,481, filed Sep. 29, 1992, now U.S. Pat. No. 5,338,299
entitled "Balloon Catheter", which is a continuation-in-part of
U.S. Ser. No. 07/871,722, filed Apr. 21, 1992, now U.S. Pat. No.
5,171,297 entitled "Balloon Catheter,"which is a continuation of
U.S. Ser. No. 07/324,913, filed Mar. 17, 1989, now U.S. Pat. No.
5,112,304, both assigned to the same assignee as the present patent
application.
Claims
We claim:
1. A balloon catheter comprising:
a. a balloon assembly;
b. means, connected to said balloon, to inflate and deflate said
balloon assembly;
c. a hub including a central tubular member with proximal and
distal ends, and a flexible polymer tube aligned and secured
through said distal end of said hub, said flexible polymer tube
having an interior lumen and being communicatively connected to
said balloon assembly;
d. a central tube including an interior lumen, said tube being
communicatively connected to said balloon, slidably aligned in said
lumen of said flexible polymer tube, and having a proximal end
extending into said hub central tubular member;
e. a piston slidably, sealably disposed in said hub central tubular
member and secured to said central tube distal end and,
f. a polymer stop disposed at said proximal end of said hub
defining a sealed air space in said hub between said piston, said
air space being compressed during inflation to aid in balloon
assembly inflation and deflation.
2. The catheter of claim 1 including a tubular telescoping assembly
of:
a. an inner telescoping tube and an outer telescoping tube between
said piston and said stop;
b. said outer telescoping tube including a lumen and an orifice
engaged into a cavity in a nipple of said piston; and,
c. said inner telescoping tube engages into an orifice of said
outer telescoping tube whereby said telescoping assembly provides
for guidance of a guidewire.
3. The catheter of claim 2 including a flared seal in said inner
telescoping tube.
4. The catheter of claim 3 wherein said flared seal is tapered
inwardly.
5. The catheter of claim 2 including a wire braid between said
piston and said nipple.
6. The catheter of claim 5 wherein said braid is a re-enforcing
non-compliant material such as stainless steel.
7. The catheter of claim 1 wherein said balloon means can be up to
12 cm in length.
8. The catheter of claim 1 wherein said central tubular means
includes an inflation port.
9. The catheter of claim 1 wherein said central tubular means tube
is a polymer such as polyimide.
10. The catheter of claim 1 wherein said stop is a polymer such as
polycarbonate.
11. The catheter of claim 1 further comprising a ring disposed
about said piston.
12. A balloon catheter comprising:
a. a balloon means;
b. an inflation means connected to said balloon means;
c. a hub means including a central tubular member with a threaded
proximal end and a distal end with a flexible conical tip, and a
flexible polymer tube aligned and secured through said distal end
of said hub, said flexible polymer tube having a lumen and being
communicatively connected to said balloon means;
d. a tube including a lumen adapted to receive an inserted
guidewire, said tube being slidably aligned in said lumen of said
flexible polymer tube;
e. a piston disposed in said hub and secured to said tube, and
having ring means for creating a pressure seal between said piston
and said hub;
f. a polycarbonate stop at said proximal end of said hub, and
g. a tubular telescoping assembly, including an inner telescoping
tube and an outer tube between said piston and said stop, said
outer tube including a lumen and an orifice engaged into a cavity
in a nipple of said piston, and said inner telescoping tube
engaging into an orifice of said outer tube whereby said
telescoping assembly guides an inserted guidewire.
13. The catheter of claim 12 including a flared seal in said inner
telescoping tube.
14. The catheter of claim 13 wherein said flared seal is tapered
inwardly.
15. The catheter of claim 12 including a wire braid between said
piston and said nipple.
16. The catheter of claim 12 wherein said balloon means can be up
to 12 cm in length.
17. A hub comprising:
a. a central tubular member with a proximal threaded end for
connection to a connector and a distal end with a flexible conical
tip and a flexible polymer tube aligned and secured
therethrough;
b. a tube including a guidewire lumen, said tube being slidably
aligned in a lumen of said flexible polymer tube;
c. a piston in said central tubular member and secured to said
tube, and having sealing ring means for creating a pressure seal
between said piston and said central tubular member;
d. a polymer stop at said proximal end of said central tubular
member; and
a telescoping tube assembly including an inner tube being connected
at one end to said stop, and an outer tube being connected at one
end to said piston, said inner and outer tubes being telescopingly
arranged with respect to each other.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to a surgical catheter, and more
particularly, a balloon catheter for enlargement of restrictions in
blood vessels, arteries or other human tissue.
2. Description of the Prior Art
Prior art balloon catheters have utilized numerous types of
structures to expand outwardly to enlarge a restriction such as in
a blood vessel, an artery or human tissue, such as the prostrate.
One problem in the past with these structures which enlarged on
inflation was that the structure did not always return to its
original diameter or initial circular configuration.
U.S. Pat. 4,56,000 to Sehjeldahl uses a thin rigid material affixed
to the distal end of a catheter to form the balloon. Particularly
in the use of nondistensible balloons, the initial profiles
achieved by wrapping the balloon are much larger than the outer
diameter of the catheter shaft and after inflation in the body, the
resulting collapsed profile may appear in cross section as a plate
extending outward from the center of the catheter. This
necessitates use of a larger device to introduce the balloon
catheter and presents complication on removal of the device from
the body and may potentially damage tissue.
U.S. Pat. No. 4,637,396 to Cook uses a knitted balloon in which the
knitting changes shape to accommodate balloon expansion. This
allows for higher pressures to be achieved in larger diameter
balloons, but does not necessarily deal with initial or collapsed
profiles.
U.S. Pat. No. 4,702,252 to Brooks uses a braided balloon which
changes in length as it expands and is accomplished by a spring at
the proximal hub end of the catheter. This design requires relative
motion between various members of the catheter which may be
difficult in long length and tortuous passageways.
U.S. Pat. 4,762,130 to Fogarty uses an embedded spring to lower the
profiles of the balloon. This design also requires relative motion
along its length and does not enhance the pressure changing
capability of the elastomeric materials.
Hubs incorporated in balloon catheters have on occasion exhibited
balloon pressure integrity breakdown where pressure is bled off
through various sealment members of the hub. One alternative
embodiment discloses an additional sealing member within an inner
chamber of the hub to provide ample pressure maintaining
capabilities for proper and constant pressure balloon
inflation.
The present invention overcomes the disadvantages of the prior art
by providing a balloon catheter with braided fibers encapsulated
between elastomeric materials and an embedded spring to provide a
low balloon profile after pressurization and depressurization.
The present invention also overcomes other disadvantages of the
prior art by providing a collapsible spring fixed between the
movable points for allowing a greater inflational radius.
The present invention also overcomes the disadvantages of the prior
art by providing a hub having inner compressible members which aid
in the deflation of an extended length balloon. One member of a
tubular telescoping assembly provides for internal guidance of a
front loaded guide wire.
SUMMARY OF THE INVENTION
The general purpose of the present invention is to provide a
balloon catheter which has a low profile in a deflated state after
pressurization to a maximum diameter, and to have components which
move relative to one another.
According to one embodiment of the present invention, there is
provided a balloon catheter with a hub at a proximal end including
a guidewire entry port, an inflation/deflation port and a tube
connected to the hub. A guidewire passage and an
inflation/deflation passage extend along the length of the tube. An
embedded spring in an elastomeric material or like material
connects to the distal end of the tube. A balloon, including
braided fibers encapsulated between an outer elastomeric material
and inner elastomeric material, connects between the end of the
tube and the distal end of the embedded spring member. The catheter
can assume either a multilumen configuration or a coaxial
configuration.
According to an alternative embodiment of the present invention,
there is provided a hub for use with a balloon catheter having an
additional seal incorporating an O-ring aligned about a piston in
direct contact with an internal chamber of the hub, thus providing
a seal to contain pressurized fluid.
According to another alternative embodiment of the present
invention, there is provided a balloon catheter distal end
incorporating a free space spring having unrestricted movement for
the purpose of returning a balloon to its streamlined relaxed
position after it has been inflated. The tip member is connected by
a movable tube connected to a piston member, which assists in
negation of the spring function during inflation, as well as
shortening of the distal tip/balloon area length to allow for
greater radiused inflation.
According to yet another embodiment of the present invention, there
is provided a hub member for use where a balloon is incorporated in
a catheter. Internal members compress to assist in balloon
inflation, and decompress to a memory position to aid in balloon
deflation by positioning an inner tube member, which attaches to
the distal end of the inflatable balloon. A telescoping assembly
having an outer tube member and a flared inner tube member assist
in guidance of a distally loaded guide wire.
Significant aspects and features of the present invention include a
low profile balloon before and after pressurization to its maximum
diameter. The differential between the balloon structure and the
inner member of the catheter is minimal, even after pressurization
and subsequent depressurization because of the combined action of
the internal spring and the elastomeric material of the balloon.
The pliability of the elastomeric material and the spring also
provide enhanced steering of the catheter during placement due to
its extreme flexibility and soft tip.
Other significant aspects and features of the present invention is
the ability to achieve higher balloon pressures, especially in
larger sized balloons used in larger vessels, arteries or
tissues.
Additional significant aspects and features of the present
invention include a braided fiber member which expands to a fixed
diameter on inflation with enhanced pressure conveying capability.
The braided fibers assist the balloon to collapse to approximately
the same profile after pressurization. Additionally, there is
enhanced cyclic durability because of the elastomeric
materials.
In addition, the use of fibers and elastomeric materials in the
balloon construction provides for a softer distal tip to the
catheter, enhancing steerability and reducing trauma. In addition,
the elastomeric material provides a construction which enhances its
ability to withstand repeated cycles of pressurization and
depressurization.
In addition, the braid can be made of a radiopaque material
obviating the need for specific bands for locating the balloon in
the body under fluoroscopy. The embedded spring also provides
structural integrity against collapse of the inner member of the
catheter during pressurization of the balloon. This enhanced
ability allows for movement of the guidewire while the balloon is
pressurized.
A further significant aspect and feature of the present invention
includes a connecting tube between the sealing member piston and
tip to distend the balloon catheter in a proximal direction where
the effect of spring tension along the balloon structure is relaxed
and negated.
Yet still another significant aspect and feature of the present
invention is a balloon structure whose length is essentially
shortened, thus allowing a greater radius of inflation.
Still another significant aspect and feature of the present
invention is a hub having an internal piston, which is pressurized,
and simultaneous energy is stored while allowing proximal
positioning of a balloon catheter inner tube to correspond with the
shortening of a balloon during inflation. Energy is released when
depressurizing to cause positioning of a balloon catheter inner
tube distally to aid in collapsing the balloon.
The hub where the energy of compression of material or air or both
is utilized to distend distally an inner catheter tube to assist in
collapsing and deflating of the balloon.
Yet another significant aspect and feature of the present invention
is a tubular extension system internally located to offer guidance
to a distally loaded guide wire which is positioned proximally.
Having thus described embodiments of the present invention, it is a
principal object hereof to provide a balloon catheter with a
balloon using braided fibers or like materials disposed between an
inner and an outer Elastomeric layer.
One object of the present invention is to provide a multilumen
balloon configuration or a coaxial balloon configuration.
Another object of the present invention is to provide a balloon
catheter which includes internal structure which functions to
deflate and collapse the balloon after pressurization to its
maximum diameter. The balloon with braided fibers between the
elastomeric material returns to its normal position, and a spring
embedded in an elastomeric material of the distal end of the
catheter further functions to collapse and return the balloon to a
normal, deflated position after pressurization. A material with a
like function can also be utilized in place of the spring.
Still another object of the present invention is to provide a
spring structure bonded at its ends and at movable points and in a
tubular area which functions to deflate and collapse the balloon
after pressurization to its maximum diameter. The balloon structure
with braided fibers between the elastomeric material returns to its
normal position aided by the spring which is unrestricted in
movement.
Yet another object of the present invention is to provide a hub
having predetermined piston travel to help determine the maximum
radius of balloon structure inflation.
Additionally, another object of the present invention is to provide
a well sealed leak proof hub for maintaining proper inflational
pressures. A further object of the present invention is to provide
a hub for use in inflation and deflation of the balloon.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects of the present invention and many of the attendant
advantages of the present invention will be readily appreciated as
the same becomes better understood by reference to the following
detailed description when considered in connection with the
accompanying drawings, in which like reference numerals designate
like parts throughout the figures thereof and wherein:
FIG. 1 illustrates a perspective view of a multilumen balloon
catheter, the present invention;
FIG. 2 illustrates a cross-sectional view of the hub of the
multilumen configuration;
FIG. 3 illustrates a cross-sectional view of the distal end of the
multilumen configuration;
FIG. 4A illustrates a cross-sectional view taken along line 4a-4a
of FIG. 3 of the multilumen configuration;
FIG. 4B illustrates a cross-sectional view taken along line 4b-4b
of FIG. 3 of the multilumen configuration;
FIG. 5 illustrates the expanded balloon of the multilumen
configuration;
FIG. 6 illustrates a perspective view of a coaxial balloon
catheter, an alternative embodiment of the present invention of the
coaxial configuration;
FIG. 7 illustrates a cross-sectional view of the hub of the coaxial
configuration;
FIG. 8 illustrates a cross-sectional view of the distal end of the
coaxial configuration;
FIG. 9A illustrates a cross-sectional view taken along line 9a-9a
of FIG. 8 of the coaxial configuration;
FIG. 9B illustrates across-sectional view taken along line 9b-9b of
FIG. 8 of the coaxial configuration;
FIG. 10 illustrates the expanded balloon of the coaxial
configuration;
FIG. 11 illustrates a cross-sectional view of a hub including an
additional sealing member of a second alternative embodiment;
FIG. 12 illustrates a cross-sectional view of a distal end of a
balloon catheter of a first alternative embodiment;
FIG. 13 illustrates the balloon structure of FIG. 12 in the
inflated position;
FIG. 14 illustrates a cross-sectional view of a third alternative
embodiment of a hub for use with extended length balloons in the
depressurized mode; and,
FIG. 15 illustrates a cross-sectional view of a hub for use with
the balloon in a pressurized mode.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a perspective view of a multilumen balloon
catheter 10, the present invention, including a hub at a proximal
end 14 with guidewire entry port 16 and an inflation/deflation port
18. This particular multilumen configuration is bilumen. A catheter
tube 20 connects to the hub 12, and includes a guidewire passage 22
and an inflation/deflation passage 24. A balloon structure 26, as
later described in detail, secures about the distal end 28. A
guidewire exit 30 is at the distal end 28 of the balloon structure
26.
FIG. 2 illustrates a cross-sectional view of the hub 12 where all
numerals correspond to those elements previously described. The
figure illustrates the hub 12 being a molded thermoplastic member
engaged about the catheter tube 20, and fused or adhesively secured
thereto. The hub 12 includes a hub chamber 32, an
inflation/deflation port 18, and a guidewire entry port 16. The
proximal end of the catheter tube 20 secures into one end of the
guidewire entry port 16. The hub 12, the catheter tube 20, the
guidewire entry port 16 and the inflation/deflation port 18 are
assembled by known processes. The guidewire passage 22, internal to
the catheter tube 20, connects between the guidewire entry port 16
and the balloon structure 26 of FIG. 3. The inflation/deflation
passage 24 connects the balloon structure 26 to the
inflation/deflation port 18 through an angled passageway 24a and
the hub chamber 32.
FIG. 3 illustrates a cross-sectional view of the distal end 28 of
the balloon catheter 10. An embedded spring 38 is embedded or fused
into elastomeric material 40 which connects to the catheter tube 20
at point 44, such as by heat fusion or adhesively. The spring can
be tensioned to a predetermined degree prior to being embedded in
the elastomeric material providing a memory for the embedded spring
38 in the elastomeric material. A balloon structure 26, which is
coaxial, includes a braided fiber 48 between an inner elastomeric
material 50 and outer elastomeric material 52, which is secured
about point 54 of the catheter tube 20 and about point 58 of the
embedded spring 38 and elastomeric material 40 containing the
guidewire passage 22, such as by heat fusion or adhesively. The
molded tip 58a provides flexibility and softness of the
catheter.
FIG. 4A illustrates a cross-sectional view taken along line 4a-4a
of FIG. 3 where all numerals correspond to those elements
previously described.
FIG. 4B illustrates a cross-sectional view taken along line 4b-4b
of FIG. 3 where all numerals correspond to those elements
previously described.
FIG. 5 illustrates the balloon catheter 10, particularly, the
balloon structure 26 in an inflated balloon position 46. All
numerals correspond to the elements previously described. The
embedded spring is compressed longitudinally and the braided fiber
has been expanded outwardly so as to enlarge along substantial
portion of its length centered approximately the mid-point of the
longitudinal length of the braided fibers. The outward expansion of
braided fibers 48 effectively shortens the length the balloon 26 in
a direction towards the proximal causing the embedded spring 38 to
compress in a like direction. The braided fibers 48 provide for
expansion to a predetermined diameter for the balloon, and form
cavity 60 about the inner surfaces of the balloon structure 26 and
the member with the embedded spring 38. After deflation of the
inflated balloon position 46 and placing a vacuum on the inflated
balloon and position 46 through the inflation/deflation port 18,
the elastomeric materials 50 and 52 about the braided fibers 48 in
combination, provide for collapsing of the balloon, as well as the
embedded spring 38 returning to a normal resting position.
Likewise, the memory of the elastomeric material materials 50 and
52 and the embedded spring 38 secondarily assist the balloon
structure in returning to a predetermined collapsed condition.
Materials of known elasticity can be selected such that the braided
fibers or the spring may not be required. The elastomeric materials
can also be selected to have different degrees of elasticity for
expansion and subsequent contraction.
MODE OF OPERATION
Referring to FIGS. 1-5, during a typical procedure, a guidewire is
placed through a body tube or tissue to be dilated, typically an
artery. The balloon catheter 10 is then introduced over the
guidewire by placing the distal end 28 of the catheter over the
proximal end of a guidewire. The balloon catheter 10 is then moved
into a position of restriction by moving the catheter over the
guidewire. Once in position, a syringe filled with a radiopaque
fluid is attached to the inflation/deflation port 18 and the
syringe plunger moved inward to inflate and pressurize the inflated
balloon position 46 by passing radiopaque fluid through the
inflation/deflation passage 24 and into the cavity 60 to--expand
the balloon structure 26 outwardly to a desired intermediate
expansion point or to a maximum expansion point allowed by the
weave structure of the braided fibers 48. After inflation, a vacuum
is introduced into the balloon by moving the plunger outward. The
balloon then returns to its resting position. The catheter is then
removed from the body. The balloon is caused to return to its
normal deflated position by the braided fibers seeking to return to
a resting position, the elasticity of the materials and the
embedded spring 38.
DESCRIPTION OF A FIRST ALTERNATIVE EMBODIMENT
FIG. 6 illustrates a perspective view of a coaxial balloon catheter
100, an alternative embodiment of the present invention, including
a hub 102 at a proximal end 104 with guidewire entry port 106 and
an inflation/deflation port 108. A coaxial catheter tube 110
connects to the hub 102, and includes a guidewire passage 112 and
an inflation/deflation passage 114. A balloon structure 116, as
later described in detail, secures about the distal end 118. A
guidewire exit 120 is at the distal end 118 of the tube 110. The
principles of the alternative embodiment are like those as
described in FIGS. 1-5.
FIG. 7 illustrates a cross-sectional view of the hub 102 where all
numerals correspond to those elements previously described. The
figure illustrates the hub 102 being a molded member engaged about
the tube 110 and fused or adhesively secured thereto. The hub 102
includes a hub chamber 122, an inflation/deflation port 108, and a
guidewire entry port 106 secured into the hub 102. The proximal end
of the tube' 110 secures into one end of the guidewire entry port
106. The hub 102, the tube 110, the guidewire entry port 106 and
the inflation/deflation entry port 108 are assembled by known
processes. An inner coaxially aligned tube 125 forms the guidewire
passage 112 and connects between the guidewire entry port 106 and
the balloon structure 116 of FIG. 8. The inflation/deflation
passage 114 is formed'between the walls of the tube 110 and the
elastomeric material 125 in a coaxial fashion. The
inflation/deflation passage 114 connects the balloon structure 116
to the inflation/deflation port 108 through the hub chamber 122 as
illustrated in FIG. 8.
FIG. 8 illustrates a cross-sectional view of the distal end 118 of
the balloon catheter 100. An embedded spring 124 is embedded in
elastomeric material 126 which connects to the tube 110 at point
128, such as by heat fusion or adhesive. The embedded spring 124
can be tensioned to a predetermined degree prior to being embedded
in the elastomeric material providing a memory for the embedded
spring in the elastomeric material. A balloon structure 116 which
is coaxial includes an inner braided fiber 132 between an inner
elastomeric material 134 and an outer elastomeric material 136,
secures about point 138 of the tube 110 and about point 140 of the
embedded spring 124 and inner elastomeric material 126 containing
the guidewire passage 112 such as by heat fusion or adhesively. The
molded tip 140a provides flexibility and softness of the
catheter.
FIG. 9A illustrates a cross-sectional view taken along line 9a-9a
of FIG. 8 where all numerals correspond to those elements
previously described.
FIG. 9B illustrates a cross-sectional view taken along line 9b-9b
of FIG. 8 where all numerals correspond to those elements
previously described.
FIG. 10 illustrates a balloon catheter 100, and particularly the
balloon 130 in an inflated mode position. All numerals correspond
to those elements previously described. The operation is similar to
that as described for FIGS. 1-5.
DETAILED DESCRIPTION OF A SECOND ALTERNATIVE EMBODIMENT
FIG. 11, a second alternative embodiment, illustrates a
cross-sectional view of a hub 150 for use with a balloon catheter
190 such as illustrated in FIG. 12 which utilizes a sealing member
152 comprised of a piston 154, an O-ring or quad ring 156, a
tapered conical surface 151, and other members as now described.
The figure illustrates the hub 150 being a molded member engaged
about a tube 158 and fused or adhesively secured thereto. The hub
150 includes a hub chamber 160, an inflation/deflation port 162, an
inflation/deflation chamber 164 between the inflation/deflation
port 162 and the hub chamber 160, a cap 166 threadingly secured
over the proximal end of the hub 150, and a guidewire entry port
168 centered through the axis of the cap 166. The proximal end of
the tube 158 secures into one end of the hub 150. The hub 150, the
tube 158, the guidewire entry port 168 and the inflation/deflation
port 162 and associated members are assembled by known processes.
An inner coaxially aligned elastomeric tube 170 aligns within the
tube 158 and serves as a guidewire passage 172 and connects between
a balloon structure such as balloon structure 116 of FIG. 8 or the
balloon structure 208 of FIG. 12 and passes through the hub chamber
160 and secures to the piston 154 of the sealing member 152 as
later described in detail. An inflation/deflation passage 174 is
formed between the walls of the outer tube 158 and the tubular
elastomeric material 170 in a coaxial fashion. The cap 166 is
threaded onto the end of the hub 150 and compresses a seal 176
through which a guidewire 178 passes. A cylindrical stop cylinder
180, including a central bore 181, aligns at the proximal end of
the hub chamber 160 and secures thereto by a bonding glue 182 or
other suitable means. A stainless steel hypo tube 179 is form fit,
press fit, bonded or otherwise secured to an annular recess 186 in
the cylindrical stop cylinder 180 and extends to align with the
tapered conical surface 156 of the sealing member 152. The hypo
tube 179 provides for passage of the guidewire 178 through the
various members, including a compressible rubber cylindrical buffer
188, a sealing member 152 and the elastomeric tube 170. A
compressible rubber cylindrical buffer 183, such as silicone
rubber, or soft plastic, and having a bore 185 slightly larger than
the hypo tube 179 acts as a shock absorber and slidingly aligns
over and about the stainless steel hypo tube 179. The piston 154 of
the sealing member 152 slidingly engages the guidewire 178 and is
secured to the proximal end of the elastomeric tube 170 by a
bonding glue 184 or other suitable means. The overall length of
piston 154, along with the length of the compressible rubber buffer
183, control the length of travel of the piston 154 and the
elastomeric tubing 170. The O-ring seal 156 about the piston 154
seals against the inner wall of the hub chamber 160 to provide a
pressure seal between proximal and distal portions of the hub
chamber 160. Pressurizing fluid injected into the
inflation/deflation port 162 is sealed from the dry proximal end of
the hub chamber 160 containing only air by the piston 154 and the
O-ring seal 156 about the piston 154. As pressurization of the
balloon takes place, the spring member of the balloon is compressed
and the overall balloon length is shortened as the elastomeric tube
170 is slidingly projected in the proximal direction by piston
action of the sealing member. The piston 154, the O-ring seal 156
and the elastomeric tube 170, accordingly slide proximally along
the guidewire 178 in the hub chamber 160 until the point of maximum
restricted balloon inflation or until the piston 154 causes the
cylindrical rubber buffer 183 to compressingly engage the
cylindrical stop cylinder 180. The sealing member 152 maintains
inflational integrity of an attached balloon catheter allowing the
balloon structure 208 pressure to remain proper and constant where
prior art devices have not maintained proper and constant pressure
due to leakage in areas such as the cap seal.
FIG. 12 illustrates a cross-sectional view of a distal end of a
balloon catheter 190 having a spring in a free space tubular area
which is unrestricted by embedding materials, such as for use with
a hub 150, such as illustrated in FIG. 11. All other numerals
correspond to those elements previously described. A tubular
elastomeric member 170 is located along the longitudinal axis and
aligns in and is bonded by a bonding glue 193 to the interior of a
tubular member 194 extending from a soft and flexible molded tip
196. A guidewire passage 198 in the molded tip 196 aligns with the
guidewire passage 200 central to the elastomeric tube 170 along the
longitudinal axis. One end of a spring 202 is embedded in the
tubular member 194 of the tip 196 and extends coaxially over and
about and along the interior of the elastomeric tube 170 until it
meets and connects to tube member 158. Tube member 158 flares
downwardly to meet the proximal end of the spring 202 and is
secured thereto by a plastic shrink tube connector 206 or by other
suitable means. The spring 202 can also butt up against tube 158
without being bonded. A coaxial balloon structure 208 aligns
coaxially over and about the elastomeric tube 170, the spring 202
and the flared end of the tube 158. The balloon structure 208
includes an inner braided fiber 210 between an inner elastomeric
material 212 and an outer elastomeric material 214 secured about
the necked down portion of the tube 158 and about the tubular
extension member 194 of the tip 196, such as by heat fusion or
adhesive bonding 216 and 218. Pressurized inflation fluid from the
inflation/deflation passage 174 transmits pressure along the area
222 between the elastomeric tube 170 and the inner elastomeric
material 212 in which the spring 202 resides to inflate the balloon
structure 208 as illustrated in FIG. 13.
FIG. 13 illustrates the balloon structure in the inflated mode of
operation where all numerals correspond to those elements
previously described. The overall length of the distal end of the
balloon catheter 190 is shortened during the inflation process due
to the qualities of the elastomeric materials incorporated. The
spring 202 is compressed along the longitudinal axis during
inflation and expands along the longitudinal axis during deflation
to aid and assist in returning the balloon structure 208 to the
streamlined position as illustrated in FIG. 12.
MODE OF OPERATION OF THE SECOND ALTERNATIVE EMBODIMENT
The mode of operation of the second alternative embodiment is best
described with reference to FIGS. 11, 12 and 13. First the maximum
amount of expansion of the balloon catheter balloon structure 208
is determined. A hub 150 having a piston 154 and a rubber buffer
cylinder 183 of suitable length is then chosen to accommodate the
maximum amount of desired balloon structure 208 inflation. The hub
150 and the balloon catheter 190 are then fit over and slid over,
about and along the guidewire 178 by known means until reaching the
point of desired inflation. The cap 166 is then tightened on the
hub threads to cause the seal 176 to compress about and to seal the
guidewire 178, thus forming the primary seal of the hub chamber 160
at a point proximal to the sealing member 152. Saline solution is
positive pressure fed through the inflation/deflation port 162 and
travels through the inflation/deflation port 162 to the hub chamber
160. Positive pressure in the hub chamber is exerted in two
directions, distally through the tube 158 to the balloon structure
208 and proximally toward the piston 154 of the sealing member 152.
As positive system pressure increases, saline pressurizes the area
222 between the inner circumferential surfaces of the inner
elastomeric material 212 causing the balloon structure 208 to
expand outwardly to enlarge restricted blood vessels, arteries, or
other bodily structures. Pressure exerted against the sealing
member 152 drives the sealing member 152 a finite distance
proximally until the sealing member 152 compresses the flexible
rubber buffer 183 against the cylindrical stop cylinder 180. As the
sealing member 152 is driven a finite distance proximally, the
inner tube 170 also correspondingly moves proximally with respect
to the tube 158 to position the balloon catheter tip 196 in a
proximal direction. This action accomplishes several tasks.
Firstly, the spring 202 is compressed, thus rendering the action of
the spring 202 null and void for this part of the procedure. This
is particularly important in that in the deflated mode, the spring
tension which causes the balloon structure to become streamlined is
overcome. Negating of the spring force cancels the stretching force
along the length of the balloon structures 208 and allows the
balloon structure 208 to be inflated outwardly without hindrance
from an outstretched spring. Secondly, this action' shortens the
balloon structure 208, thus allowing a greater radius of expansion
for the balloon structure 208 as it is suspended between two points
216 and 218 which are not fixed as in prior art devices, butt which
are laterally moveable.
Deflation of the balloon structure 208 is accomplished in a reverse
order. Pressure at the inflation/deflation port 162 is reduced to
zero or can be reduced to a negative pressure if so required. The
sealing structure 152 and the inner tube 170 then return to their
relaxed mode position with the release of positive system pressure
and with assistance from the compressed spring 202, which then
returns to its normal length which also returns the balloon
structure 208 to its original streamlined low profile position.
DESCRIPTION OF A THIRD ALTERNATIVE EMBODIMENT
FIG. 14 illustrates a cross-sectional view of a hub 250 for use
with a balloon or an extended length balloons of, for purposes of
example only, lengths up to 12 cm. Members interior to the hub 250
assist in returning a balloon, such as a balloon of an extended
length balloon to a substantially full and uninflated length of
substantially original cross section. The hub 250 includes a
central tubular member 252 having at one end a threaded portion 254
for connection to a Touhy Borst connector 255, and on the opposite
end a flexible rubber like conical tip 256 affixed to the central
tubular member 252 over and about an annular rim 258. An inflation
port 260, having a connector flange 262, aligns at an angle to the
central tubular member 252 and is plumbed to the central bore 264
of the central tubular member 252. A flexible polymer tube 266
aligns and suitably secures by bonding glue 267 through the distal
end 268 of the hub 250. A polyimide tube 270, having a guidewire
lumen 272, slidingly aligns in the lumen 274 of the polymer tube
266, and is secured by suitable bonding glue 271 to a piston 276.
Sufficient clearance between the interior wall of the flexible
polymer tube 266 and the outer wall of the polyimide tube 270
allows for inflation of a balloon at the distal end of the balloon
catheter. The polyimide tube 270 secures by a bonding glue 271 to
the piston 276 aligned in the central bore 264. A connection nipple
277 extends from one side of the piston 276. The piston 276 is
sealed against the interior walls of the central bore 264 by a quad
ring seal 278, thus creating a sealed pressurized system including
a balloon as previously illustrated at the end of the flexible
polymer tube 266, the central bore 264, the inflation port 260, and
an appropriate connected pressurizing apparatus. A polycarbonate
stop 280 aligns within the central bore 264 in the vicinity of the
threaded portion 254, and includes a connection nipple 282 and a
central lumen 284 through-which a guidewire can be passed. The
Touhy Borst connector 255 applies pressure against an elastomeric
gasket 257 and the silicone bumper to seal the Touhy Borst
connector 255 to the central bore 264. A polyurethane tube 286
aligns over and is secured, such as by bonding glue 289 and 291,
between connection nipples 282 and 277, thus connecting the
polycarbonate stop 280 and the piston 276. A stainless steel wire
braid 288 secures over and about the length of the polyurethane
tube 286 by crimp rings 290 and 292, thus furthering the connection
between the polycarbonate stop 280 and the piston 276.
A tubular telescoping assembly 298 comprised of an inner
telescoping tube 300 and an outer telescoping tube 302 aligns and
secures between the polycarbonate stop 280 and the piston 276. The
outer telescoping tube 302 including a lumen 304 and an orifice 306
at the end of lumen 304 is press fit into a cavity 308 in the
nipple 277. Correspondingly, the inner telescoping tube 300 having
a lumen 310 and a flared seal member 312 is press fit into a cavity
314 in the end of nipple 282 of the silicone bumper 280. The inner
telescoping tube 300 slidingly engages orifice 306 of the outer
telescoping tube 302. The tubular telescoping assembly 298 offers
guidance for a guide wire aligned through the central bore 284 of
the polycarbonate stop 280 for ease of alignment with lumen 272 of
the polyimide tube 270. A flared seal member 312 is tapered
inwardly to intersect with lumen 310. The flared seal member 312
having an inwardly tapered surface 313 assists in guidance of a
front loaded guide wire inserted in the distal end of lumen 272 and
moved proximally through lumen 304, 310, 284 gasket 257 and through
the Touhy Borst connector 255. The tubular telescoping assembly 298
also stabilizes the polyurethane tube 286 when the piston 276 is
positioned as illustrated in FIG. 15. Curling or kinking or other
misalignment of the polyurethane tube 286 and of the stainless
steel wire braid 288 is eliminated as the tubular telescoping
assembly 298 acts as a horizontal guide along the length of the
central bore 264.
MODE OF OPERATION OF THE THIRD ALTERNATIVE EMBODIMENT
FIG. 15 illustrates the mode of operation of the hub 250 in
conjunction with a balloon catheter, including a balloon of
extended length, such as a length of up to 12 cm. A pressurized
saline solution applied to the inflation port 260 flows through the
lumen 274 of the flexible polymer tube 266 to inflate an extended
length balloon at the distal end of the balloon catheter. As the
balloon is inflated, the polyimide tube 270 is forced to retract
proximally partly by the shortening of the expanding balloon which
develops a shorter length during inflation, thus driving the
polyimide tube 270 proximally, and partly by the pressurized saline
force driving the piston 276 proximally. The driving of the piston
276 proximally cause several occurrences. Firstly, the polyurethane
tube 286 and the stainless steel wire braid 288 are compressed
along their common axis along their length as the piston is driven
proximally. This compression applied to the ends of the
polyurethane tube 286 and the stainless steel wire braid 288,
causes the ends to expand from their position of memory
concentrically and outwardly about their common axis, and also to
be compressed to a shorter longitudinal dimension. Energy is stored
during the compression process, and is held in readiness by the
pressure exerted by the saline pressurizing medium. Secondly, air
captured in the central bore 264 between the piston 276 and the
polycarbonate stop 280 is compressed as the piston 276 is forced
proximally and is also held in readiness. Thus, energy is stored by
the compressed polyurethane tube 286, the surrounding compressed
stainless steel wire braid 288, and also by compressed air in the
portion of the central bore proximal to the piston 276. During
compression the outer telescoping tube 302 is driven proximally
along the inner telescoping tube 300.
When it is desired to collapse and retract the balloon at the
distal end of a balloon catheter, pressure to the inflation port
260 is released thereby releasing stored energies and causing the
polyimide tube 270 to be driven distally to enable full and proper
balloon collapsing. This enablement is caused by the stored energy
being released. The compression energy of the compressed
polyurethane tube 286 and the stainless steel wire braid 288
returning to their memory positions caused the polyimide tube 270
to be driven distally. The compression energy stored by the
compressed air proximal to the piston 276 also aids in movement of
the polyimide tube 270 distally to also assist in collapsing of the
balloon.
Various modifications can be made to the present invention without
departing from the apparent scope hereof.
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